Iowa Admin. Code r. 567-43.9 - Enhanced filtration and disinfection requirements for surface water and IGW systems serving at least 10,000 people
(1)
General requirements.
a.
Applicability. The
requirements of this rule constitute national primary drinking water
regulations. This rule establishes the filtration and disinfection requirements
that are in addition to criteria under which filtration and disinfection are
required in 567-435. (455B). The
requirements of this rule are applicable, beginning January 1, 2002, to all
public water systems using surface water or groundwater under the direct
influence of surface water , in whole or in part, and which serve at least
10,000 people. This rule establishes or extends treatment technique
requirements in lieu of maximum contaminant levels for the following
contaminants:Giardia lamb Ha, viruses, heterotrophic plate
count bacteria,
Legionella , Cryptosporidium , and turbidity.
Each surface water or groundwater under the direct influence of surface water
system serving at least 10,000 people must provide treatment of its source
water that complies with these treatment technique requirements and they are in
addition to those identified in subrule 43.5(1). The treatment technique
requirements consist of installing and properly operating water treatment
processes that reliably achieve:
(1) At least
99 percent (2-log) removal of
Cryptosporidium between a point
where the raw water is not subject to recontamination by surface water runoff
and a point downstream before or at the first customer for filtered
systems.
(2) Compliance with the
profiling and benchmark requirements under 43.9(2).
(3) The department may require other surface
water or groundwater under the direct influence of surface water systems to
comply with this rule, through an operation permit.
b.
Compliance determination.
A public water system subject to the requirements of this rule is
considered to be in compliance with the requirements of 43.9(1)
"a" if it meets the applicable filtration requirements in
either 43.5(3) or 43.9(3) and the disinfection requirements in 43.5(2) and
43.6(2).
c.
Prohibition of
new construction of uncovered intermediate or finished water storage
facilities. Systems that are required to comply with this rule may
construct only covered intermediate or finished water storage facilities. For
the purposes of this rule, an intermediate storage facility is defined as a
storage facility or reservoir after the clarification treatment
process .
d.
Systems with
populations that increased after January 1, 2002, to more than 10,000 people
served. Systems using surface water or influenced groundwater sources
that did not conduct optional monitoring under 43.9(2) because they served
fewer than 10,000 persons when such monitoring was required, but serve more
than 10,000 persons prior to January 1,2005, must comply with 43.9(1), 43.9(3),
43.9(4), and 43.9(5). These systems must also consult with the department to
establish a disinfection benchmark. A system that decides to make a significant
change to its disinfection practice as described in 43.9(2)"c"
(1)"1" through "4" must consult with the department prior to making such a
change.
(2)
Disinfection profiling and benchmarking.
a.
Determination of systems required
to profile. A public water system subject to the requirements of this
rule must determine its total trihalomethane (TTHM) and haloacetic acid (HAA5)
annual averages using the procedures listed below. The annual average is the
arithmetic average of the quarterly averages of four consecutive quarters of
monitoring. Both the TTHM and HAA5 samples must be collected as paired samples
during the same time period in order for each parameter to have the same annual
average period for result comparison. A paired sample is one that is collected
at the same location and time and is analyzed for both TTHM and HAA5
parameters.
(1) Allowance of information
collection rule data. Those systems that collected data under the provisions of
the federal Information Collection Rule listed in Code of Federal Regulations
Title 40, Part 141, Subpart M, must use the results of the TTHM and HAA5
samples collected during the last four quarters of monitoring required under 40
CFR 141.142 . The system must have submitted the results of the samples
collected during the last 12 months of required monitoring.
(2) Systems that have not collected TTHM and
HAA5 data under 43.9(2)"a"(1) Those systems that have not
collected four consecutive quarters of paired TTHM and HAA5 samples as
described under 43.9(2) "a "(1) must comply with all other provisions of this
subrule as if the HAA5 monitoring had been conducted and the results of that
monitoring required compliance with 43.9(2)"b. " The system
that elects this option must notify the department in writing of its decision.
(3) The department may require
that a system use a more representative annual data set than the data set
determined under 567-subparagraph 42.9(2)"a " (1) for the
purpose of determining applicability of the requirements of this
subrule.
(4) Profiling
determination criteria. Any system having either a TTHM annual average greater
than 0.064 mg/L or an HAA5 annual average greater than 0.048 mg/L during the
period identified in 43.9(2) "a "(1) through (3) must comply
with 43.9(2)"b. "
b.
Disinfection profiling.
(1) Applicability. Any system that meets the
criteria in 43.9(2)"a " (4) must develop a disinfection
profile of its disinfection practice for a period of up to three
years.
(2) Monitoring requirements.
The system must monitor daily for a period of 12 consecutive calendar months to
determine the total logs of inactivation for each day of operation, based on
the CT99.9 values in Tables 1 through 8 in Appendix A,
as appropriate, through the entire treatment plant. This system must begin this
monitoring as directed by the department . As a minimum, the system with a
single point of disinfectant application prior to entrance to the distribution
system must conduct the monitoring in 43.9(2) "b"(2)"1"
through "4." A system with more than one point of disinfectant application must
conduct the monitoring in 43.9(2)"b"(2)"1" through "4" for
each disinfection segment. The system must monitor the parameters necessary to
determine the total inactivation ratio, using analytical methods in
43.5(4)"a" as follows:
1.
The temperature of the disinfected water must be measured once per day at each
residual disinfectant concentration sampling point during peak hourly
flow.
2. If the system uses
chlorine, the pH of the disinfected water must be measured once per day at each
chlorine residual disinfectant concentration sampling point during peak hourly
flow.
3. The disinfectant contact
time(s) ("T") must be determined for each day during peak hourly
flow.
4. The residual disinfectant
concentration (s) ("c") of the water before or at the first
customer and prior to each additional point of disinfection must be measured
each day during peak hourly flow.
(3) Use of existing data. A system that has
existing operational data may use those data to develop a disinfection profile
for additional years, in addition to the disinfection profile generated under
43.9(2)"b " (2). Such systems may use these additional yearly
disinfection profiles to develop a benchmark under the provisions of
43.9(2)"c." The department must determine whether these
operational data are substantially equivalent to data collected under the
provisions of 43.9(2)"b " (2). These data must also be
representative of inactivation through the entire treatment plant and not just
of certain treatment segments.
(4)
Calculation of the total inactivation ratio. The system must calculate the
total inactivation ratio as follows, using the CT99.9
values from Tables 1 through 8 listed in Appendix A:
1. If the system uses only one point of
disinfectant application , the system may determine the total inactivation ratio
for the disinfection segment based on either of the following two methods:
* Determine one inactivation ratio (CTcalc/CT99.9) before or at the first customer during peak hourly flow.
* Determine successive CTcalc/CT99.9
values, representing sequential inactivation ratios, between the
2. If the system uses more than
one point of disinfectant application before the first customer, the system
must determine the CT value of each disinfection segment immediately prior to
the next point of disinfectant application , or for the final segment, before or
at the first customer, during peak hourly flow. The
CTcalc/CT99.9) value of each segment and
[SIGMA](CTcalc/CT99.9) must be calculated using the
method in 43.9(2) "b"(4)"1"
3. The system must determine the total logs
of inactivation by multiplying the value calculated in
43.9(2)"b" (4)"1" or "2" by 3.0.
(5) Systems using chloramines or ozone. A
system that uses either chloramines or ozone for primary disinfection must also
calculate the logs of inactivation for viruses using a method approved by the
department .
(6) Profile retention
requirements. The system must retain disinfection profile data in graphic form,
as a spreadsheet, or in some other format acceptable to the department for
review as part of sanitary surveys conducted by the department . The department
may require the system to submit the data to the department directly or as part
of a monthly operation report.
c.
Disinfection
benchmarking.
(1) Significant change
to disinfection practice. Any system required to develop a disinfection profile
under the provisions of 43.9(2)"a" or"b" that
decides to make a significant change to its disinfection practice must obtain
department approval prior to making such change. Significant changes to
disinfection practice are:
1. Changes to the
point of disinfection ;
2. Changes
to the disinfectant (s) used in the treatment plant;
3. Changes to the disinfection process ;
and
4. Any other modification
identified by the department .
(2) Calculation of the disinfection
benchmark. Any system that is modifying its disinfection practice must
calculate its disinfection benchmark using the procedure specified below:
1. For each year of profiling data collected
and calculated under 43.9(2)"b, " the system must determine
the lowest average monthly
Giardia lamblia inactivation in each
year of profiling data. The system must determine the average
Giardia
lamblia inactivation for each calendar month for each year of
profiling data by dividing the sum of daily
Giardia lamblia
inactivation by the number of values calculated for that month.
2. The disinfection benchmark is the lowest
monthly average value (for systems with one year of profiling data) or average
of lowest monthly average values (for systems with more than one year of
profiling data) of the monthly logs of
Giardia lamblia
inactivation in each year of profiling data.
(3) A system that uses either chloramines or
ozone for primary disinfection must also calculate the disinfection benchmark
for viruses using a method approved by the department .
(4) The system must submit the following
information to the department as part of its consultation process :
1. A description of the proposed
change;
2. The disinfection profile
for
Giardia lamblia (and, if necessary, viruses) under
43.9(2)"b " and the disinfection benchmark as required by
43.9(2)"c"(2); and
3. An analysis of how the proposed change
will affect the current levels of disinfection .
(3).
Filtration .
a.
Conventional filtration treatment
or direct filtration .
(1) Turbidity
requirement in 95 percent of samples. For systems using conventional filtration
or direct filtration , the turbidity level of representative samples of a
system's filtered water (combined filter effluent or CFE) must be less than or
equal to 0.3 NTU in at least 95 percent of the measurements taken each month,
measured as specified in 43.5(4)"a"(1) and 43.5(4)"b
". (1)
(2) Maximum
turbidity level. The turbidity level of representative samples of a system's
filtered water (combined filter effluent or CFE) must at no time exceed 1 NTU,
measured as specified in 43.5(4)"a"(1) and 43.5(4)"b
"(1). If at any time the combined filter effluent turbidity exceeds 1
NTU, either in a grab sample used for compliance or in a continuously monitored
flow, the system must inform the department as soon as possible, but no later
than 24 hours after the exceedance is known, in accordance with the public
notification requirements under 567-subparagraph 42.1(3)"b "
(3).
(3) Systems with
lime-softening treatment. A system that uses lime softening may acidify
representative samples prior to analysis using a protocol approved by the
department .
b.
Filtration technologies other than conventional filtration treatment , direct
filtration , slow sand filtration , or diatomaceous earth filtration .
The department may allow a public water system to use a filtration technology
not listed in 43.9(3) "a" or 43.5(3)"c" or"d"
if it demonstrates to the department , using pilot plant studies or other means,
that the alternative filtration technology, in combination with disinfection
treatment that meets the requirements of 43.5(2), consistently achieves 99.9
percent removal or inactivation of
Giardia lamblia cysts, 99.99
percent removal or inactivation of viruses, and 99 percent removal
of
Cryptosporidium oocysts and the department approves the use
of the filtration technology. For each approval, the department will set
turbidity performance requirements that the system must meet at least 95
percent of the time and the requirement that the system shall not exceed at any
time at a level that consistently achieves 99.9 percent removal or inactivation
of
Giardia lamblia cysts, 99.99 percent removal or inactivation
of viruses, and 99 percent removal of
Cryptosporidium oocysts.
(4)
Filtration
sampling requirements.
a.
Monitoring requirements for systems using filtration treatment. In
addition to monitoring required by 43.5(4), a public water system subject to
the requirements of this rule that provides conventional filtration treatment
or direct filtration must conduct continuous monitoring of turbidity for each
individual filter using an approved method in 43.5(4)"a"(1)
and must calibrate turbidimeters at least every 90 days with a primary
standard. The calibration of each turbidimeter used for compliance must be
verified at least once per week with a primary standard, secondary standards,
or the manufacturer's proprietary calibration confirmation device or by a
method approved by the department . If the verification is not within plus or
minus 0.05 NTU for measurements of less than or equal to 0.5 NTU, or within
plus or minus 10 percent of measurements greater than 0.5 NTU, then the
turbidimeter must be recalibrated. Systems must record the results of
individual filter monitoring every 15 minutes.
b.
Failure of the continuous
turbidity monitoring equipment . If there is a failure in the
continuous turbidity monitoring equipment , the system must conduct grab
sampling every four hours in lieu of continuous monitoring until the
turbidimeter is repaired and back online. A system has a maximum of five
working days after failure to repair the equipment , or else it is in
violation.
(5)
Reporting and record-keeping requirements. In addition to the
reporting and record-keeping requirements in 567-paragraph
42.4(3)"c," a system subject to the requirements of this rule
that provides conventional filtration treatment or direct filtration must
report monthly to the department the information specified in
43.9(5)"a" and"b" beginning January 1, 2002.
In addition to the reporting and record-keeping requirements in 567-paragraph
42.4(3)"c", a system subject to the requirements of this rule
that provides filtration approved under 43.9(3)"b " must
report monthly to the department the information specified in 43.9(5) "a"
beginning January 1, 2002. The reporting in 43.9(5) "a" is in lieu of the
reporting specified in 567-subparagraph 42.4(3)"c".(1)
a.
Turbidity. Turbidity
measurements as required by 43.9(3) must be reported in a format acceptable to
the department and within ten days after the end of each month that the system
serves water to the public. Information that must be reported includes:
(1) The total number of filtered water
(combined filter effluent or CFE) turbidity measurements taken during the
month;
(2) The number and
percentage of filtered water (combined filter effluent or CFE) turbidity
measurements taken during the month which are less than or equal to the
turbidity limits specified in
43.9(3)"a"or"b"; and
(3) The date and value of any combined filter
effluent or CFE turbidity measurements taken during the month which exceed 1
NTU for systems using conventional filtration treatment or direct filtration or
which exceed the maximum level set by the department under 43.9(3)"b.
"
(4) The dates and
summary of calibration and verification of all compliance
turbidimeters.
b.
Individual filter turbidity monitoring. Systems must maintain
the results of individual filter turbidity per monitoring taken under 43.9(4)
for at least three years. Systems must report to the department that they have
conducted individual filter turbidity monitoring under 43.9(4) within ten days
after the end of each month that the system serves water to the public. Systems
must report to the department individual filter turbidity measurement results
taken under 43.9(4) within ten days after the end of each month that the system
serves water to the public only if measurements demonstrate one or more of the
conditions specified in 43.9(5)"b"(1) through (4). Systems
that use lime softening may apply to the department for alternative exceedance
levels for the levels specified in 43.9(5)"b" (1) through (4)
if they can demonstrate that higher turbidity levels in individual filters are
due to lime carryover only and not due to degraded filter performance.
(1) For any individual filter that has a
measured turbidity level of greater than 1.0 NTU in two consecutive
measurements taken 15 minutes apart, the system must report the filter number,
the turbidity measurement, and the date(s) on which the exceedance occurred. In
addition, the system must either produce a filter profile for the filter within
seven days of the exceedance (if the system is not able to identify an obvious
reason for the abnormal filter performance) and report that the profile has
been produced or report the obvious reason for the exceedance.
(2) For any individual filter that has a
measured turbidity level of greater than 0.5 NTU in two consecutive
measurements taken 15 minutes apart anytime following the first four hours of
continuous filter operation after the filter has been backwashed or otherwise
taken offline, the system must report the filter number, the turbidity, and the
date(s) on which the exceedance occurred. In addition, the system must either
produce a filter profile for the filter within seven days of the exceedance (if
the system is not able to identify an obvious reason for the abnormal filter
performance) and report that the profile has been produced or report the
obvious reason for the exceedance.
(3) For any individual filter that has a
measured turbidity level of greater than 1.0 NTU in two consecutive
measurements taken 15 minutes apart at any time in each month of three
consecutive months, the system must report the filter number, the turbidity
measurement, and the date(s) on which the exceedance occurred. In addition, the
system must conduct a self-assessment of the filter within 14 days of the
exceedance and report that the self-assessment was conducted. The
self-assessment must consist of at least the following components: assessment
of filter performance; development of a filter profile ; identification and
prioritization of factors limiting filter performance; assessment of the
applicability of corrections; and preparation of a filter self-assessment
report.
(4) For any individual
filter that has a measured turbidity level of greater than 2.0 NTU in two
consecutive measurements taken 15 minutes apart at any time in each month of
two consecutive months, the system must report the filter number, the turbidity
measurement, and the date(s) on which the exceedance occurred. In addition, the
system must arrange for a comprehensive performance evaluation to be conducted
by the department or a third party approved by the department no later than 30
days following the exceedance and have the evaluation completed and submitted
to the department no later than 90 days following the exceedance.
c.
Additional reporting
requirement for turbidity combined filter effluent.
(1) If at any time the turbidity exceeds 1
NTU in representative samples of filtered water (combined filter effluent or
CFE) in a system using conventional filtration treatment or direct filtration ,
the system must consult with the department as soon as practical, but no later
than 24 hours after the exceedance is known, in accordance with the public
notification requirements under 567-subparagraph 42.1(3)"b "
(3).
(2) If at any time the
turbidity in representative samples of filtered water (combined filter effluent
or CFE) exceeds the maximum level set by the department under 43.9(3)"b
" for filtration technologies other than conventional filtration
treatment , direct filtration , slow sand filtration , or diatomaceous earth
filtration , the system must consult with the department as soon as practical,
but no later than 24 hours after the exceedance is known, in accordance with
the public notification requirements under 567-subparagraph
42.1(3)"b" (3).
Notes
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